This invention relates to liquid fuel stoves and, in particular, to portable liquid fuel stoves for military use.
Portable stoves are used for a variety of purposes such as military operations. They are used in range ovens, steam tables, tray ration heaters, field sanitation equipment and stock pot heating racks. These appliances perform such functions as roasting, grilling, broiling, frying, heating water and other liquids and baking. They are typically utilized in such field equipment as tents, other shelters, containerized mobile kitchens and mobile kitchen trailers. These appliances may also be used in an open field without the benefit of shelter.
Such stoves may operate under difficult field conditions and must be reliable in operation and perform to a high level in order to meet the demands of some users.
Some previous portable stoves have had serious problems and disadvantages. They sometimes take a long time to ignite, are not reliable and may perform inadequately if not operated according to strict procedures. Some are not capable of being re-fueled in an appliance, making it necessary to remove the stoves in order to fuel them. This is both labor intensive and inconvenient in the relatively tight quarters of field kitchens for example. Moreover, some are also labor intensive to operate and maintain. They utilize a pressurized fuel tank which contains an explosive fuel. This may present a potential hazard.
Currently there is a demand for a replacement for certain types of portable stoves. The replacement units preferably should be robust in terms of durability. Service and maintenance should be simple, as they often must be conducted by a technically untrained stove operator. Field service should not require specialized tools. Cleaning should be accomplished by simple procedures such as wiping the stoves down with a soapy wet cloth. Such stoves must be rugged enough to withstand transportation as unrestrained cargo in ground vehicles, often moving over rough terrain.
Also, such units should be capable of burning certain fuels, such as military JP-8 fuel, which some previous stoves are incapable of burning. Also, for some applications, a multifuel stove is desired which would be capable of burning such alternative fuels as JP-8; DFA, DF-1 and DF-2 (military diesel fuels), #1 and #2 diesel fuel, kerosene and JP-5.
Accordingly, it is an object of the invention to provide an improved stove adaptable for a wide variety of purposes including installation in existing appliances such as range ovens, steam tables, tray ration heaters, field sanitation equipment and stock pot heating racks.
It is also an object of the invention to provide an improved stove which is capable of performing such functions as roasting, grilling, broiling, frying, heating water and other liquids and baking.
It is also an object of the invention to provide an improved stove which is capable of being utilized in such field equipment as tents, other shelters, containerized mobile kitchens and mobile kitchen trailers.
Is a further object of the invention to provide an improved stove which is capable of burning JP-8 fuel.
It is a still further object of the invention to provide improved stove which is capable of burning a variety of liquid fuels such as JP-8, diesel fuels or kerosene.
It is still further object of the invention to provide an improved stove which is easy to ignite, reliable to operate and easy to maintain.
It is still further object of the invention to provide an improved stove which can be refueled in the appliance and which does not have a pressurized fuel tank.
In accordance with these objects, there is provided, according to the invention, a stove apparatus having a frame with an interior opening. There is a burner mounted within the opening. The apparatus includes an air compressor mounted on the frame. There is an air conduit which extends between the compressor and the burner. A liquid fuel container is mounted on the frame within the opening. A fuel conduit extends between the container and the burner. A heat shield extends about the burner and separates the burner from the fuel container. A fuel control valve controls a flow of fuel from the fuel container to the burner. There is a control device for controlling output of the compressor.
In one embodiment, the apparatus has a movable front access panel and controls mounted on the access panel.
There may be a knob which simultaneously regulates the fuel control valve and speed of the compressor.
Preferably the compressor has a suction port. The apparatus then includes a suction conduit connecting the suction port to the fuel container and to a valve operatively connected to the suction conduit. The compressor can selectively draw fuel into the fuel container for refueling the stove.
The fuel container may have a vent body mounted thereon. The suction conduit is connected to the vent body. The vent body is mounted on top of the container and has a fuel tube extending to near the bottom of the container. There may be a float slidingly mounted on the tube and a first switch operatively connected to the compressor. The float has means for actuating a switch to stop operation of the compressor when fuel is near the top of the container.
In one preferred embodiment the body has means for preventing fuel from entering the suction conduit from the container. This includes a chamber having a top and a bottom. There is a check valve seat at the top of the chamber. A check valve ball, buoyant in the fuel, is movably mounted in the chamber. A conduit extends from near the bottom of the chamber to the container. If fuel is drawn into the chamber, the check valve ball floats to the top of the chamber and blocks the fuel from entering the suction conduit. For example, the valve seat may be conical in shape, tapering inwards towards the suction conduit. The chamber may have a frustum shaped portion adjacent the seat. The frustum shaped portion has walls tapering inwardly towards the valve seat which are less acutely sloped than the valve seat.
Stoves according to the invention offers significant advantages over the prior art. They utilize a non-pressurized fuel system which is inherently safer than a pressurized system. The stoves can be refueled in the appliances. They are also capable of burning JP-8 fuel or, alternatively, a variety of different fuels such as JP-8 fuels, military diesel fuels, kerosene or JP-5.
Stoves according to the invention also may include electronic ignition which facilitates starting of the appliance. They are easy to operate and reliable in operation. Warming up time is reduced from 30 minutes to 120 minutes in some prior art devices to approximately 2 minutes. The startup is smoke-free and they are capable of shutting off immediately without going through any elaborate shutdown procedure.